NC0004987_Addendum to Application Permit 2015_20150520

tDUKE Duke Energy
ENERGY® 526 South Church Street
CAROLINAS Charlotte, NC 28202
Mailing Address:
EC3XP/P.O.Box 1006
Charlotte, NC 28201-1006
r ECEIVED/DENR/DWR
May 18, 2015
MAY. 202015
Mr. Jeffrey Poupart, Section Chief Water Quality
NC Division of Water Resources Permitting Section
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Addendum to NPDES Waste Water Permit Application Permit
Chemical characterization of water for dewatering of ash basins
Marshall Steam Station
NC0004987
Catawba County
Dear: Mr. Poupart,
Duke Energy hereby formally submits the attached characterization of ash basin free water and
ash basin interstitial water for the subject facility. These results were previously submitted to
your staff via email on May 8, 2015.
As discussed in various recent meetings between Duke and DENR staff, while there are no
current plans or commitments to dewater the ash basins at the subject facility, Duke request
that language be included in our re-issued NPDES permit to accommodate that activity if it an
activity the company decides to undertake within the term of the re-issued permit. As discussed
in the meetings, "dewatering" in the NPDES permits refers to the removal of interstitial water
from the ash basin(s).
The attached table provides results of chemical analysis of both ash basin free water and ash
basin interstitial water. The ash basin free water samples were taken at different depths in the
ash basin. The ash basin interstitial water samples results are presented 1.) without additional
treatment and 2.) after additional treatment with three different size filters.
The following definitions may be useful as you consider these activities:
Ash basin free water: Water in an ash basin located above the settled layer of ash.
Ash basin free water has undergone treatment in the ash basin, has the same general
characteristics as water routinely discharged from the facility in accordance with the
existing NPDES permit, is largely devoid of Total Suspended Solids and is expected to
meet all applicable NPDES permit limits.
Ash basin interstitial water: Water in an ash basin that is located within the pore
space of accumulated wastewater sludge or slurry. Ash basin interstitial water must be

removed from an ash basin by some means such as trenching, well points, etc. and
may require additional treatment before being released to the environment.
If you have any questions regarding this submittal, please contact Mr. Shannon Langley at(919)
546-2439 or [e-mail].
I certify, under penalty of law, that this document and all attachments were prepared under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly gather and
evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or
those persons directly responsible for gathering the information, the information submitted is, to the best of my
knowledge and belief true,accurate, and complete. I am aware that there are significant penalties for
submitting false information, including the possibility of fines and imprisonment for knowing violations.
Sincerely,
Harry K. Sideris
Senior Vice President
Environmental, Health and Safety
attachment

Marshall
Dewatering Data Submittal
May 2015
Marshall Ash Marshall Marshall Ash Basin- Ash Basin- Ash Basin- Ash Basin
Ash Basin 2 Ash Basin 4 Interstitial with Interstitial with interstitial with
Bason 0.3m Interstitial
meters meters 20 u filter 10 u filteru 0.45 u filter
Comoonen% Units Result Result Result Result Result Result Result
Oil and Grease mg/L < 5
NO2+NO3(Colorimetric) mg-N/l 0.363 0.31 0.42 0.056 0.018 0.021 0.028
TKN(Colorimetric) mg-N/L 1.2 0.97 1.1 4.2 3.8 4.3 4.8
Bromide mg/L 18.23 20 28.6 8.727 8.738 8.701 8.753
Chloride mg/L 184.7 195 288 115.3 114.3 115.8 115.1
`_ Fluoride __ _ _ mg/L 0.57 0.63 0.83 2.773 2.77 2.77 2.78 __
Sulfate mg/L 120.6 142 149 76.07 75.55 74.92 75.59
Aluminum(Al) mg/L 0.474 0.81 0.16 0.254 0.236 _ 0.16 < 0.005
Barium(Ba) mg/L 0.07 0.07 0.08 0.492 0.498 0.475 0.407
Boron(B) mg/L 4.28 4.64 6.27 5.06 5.13 4.92 5.02
Calcium(Ca) mg/L 92.7 102 133 126 128 125 125
Iron(Fe) mg/L 0.671 1.12 0.36 8.5 8.55 8.07 0.479
Magnesium(Mg) mg/L 43.2 46.7 63.9 52.1 52.9 51.9 51.8
Manganese(Mn) mg/L 0.713 0.98 1.25 1.12 1.14 1.09 1.08
Phosphorus(P) mg/L 0.037 0.04 0.03 0.394 0.397 0.375 0.097
Zinc(Zn) mg/L 0.018 0.05 0.02 0.006 < 0.005 < 0.005 < 0.005
Antimony(Sb) ug/L < 1 < 1 < 1 < 1 < 1 < 1 < 1
Arsenic(As) ug/L 7.23 7.59 4.03 3560 3480 , 3550 1930
Cadmium(Cd) ug/L < 1 < 1 < 1 < 1 < 1 < 1 < 1
Chromium(Cr) ug/L < 1 < 1 < 1 < 1 < 1 , < 1 < 1
Copper(Cu) ug/L 2.4 4.99 2.48 1.54 1.1 i < 1 < 1
Lead(Pb) ug/L < 1 < 1 < 1 < 1 < 1 < 1 < 1
Molybdenum(Mo) ug/L 20.7 24.5 19 854 806 841 823
Nickel(Ni) ug/L 10.8 14.8 13.5 2.18 1.23 < 1 < 1
Selenium(Se) ug/L 2.45 3.01 3.15 1.22 1.01 1.07 1.03
Thallium(TI)Low Level ug/L 0.508 0.38 0.38 < 0.2 0.828 0.365 < 0.2
Vanadium(V) ug/L 1.73 1.72 < 1 1.33 1.07 1.05 < 1
Mercury(CVAFS) ng/L 1.52 1.97 0.56 < 2 < 2 < 0.5 < 0.5
TDS mg/L 620 670 920 660 660 680 680
TSS mg/L 8 14 6 26 26 19 < 10